ADM6821

www.DataSheet4U.com Preliminary Technical Data FEATURES Low Voltage Supervisory Circuits with Watchdog & Manual Reset in 5-Lead SOT-23 ADM6821–ADM6825 FUNCTIONAL BLOCK DIAGRAM VCC Precision Low Voltage Monitoring down to 1.8V 9 Reset Threshold Options: 1.58V to 4.63V 140ms (Min) Reset Timeout Watchdog Timer with 1.6s Timeout Manual Reset Input Reset Output Stages Push-Pull Active-Low Open-Drain Active-Low Push-Pull Active-High Low Power Consumption (3µA) Guaranteed Reset Output valid to VCC=1V Power Supply Glitch Immunity Specified from -40°C to +125°C 5-Lead SOT-23 Package ADM6821 VCC VREF RESET GENERATOR RESET MR DEBOUNCE WATCHDOG DETECTOR GND WDI APPLICATIONS Microprocessor Systems Computers Controllers Intelligent Instruments Portable Equipment GENERAL DESCRIPTION The ADM6821-ADM6825 are supervisory circuits which monitor power supply voltage levels and code execution integrity in microprocessor-based systems. As well as providing power-on-reset signals, an on-chip watchdog timer can reset the microprocessor if it fails to strobe within a preset timeout period. A reset signal can also be asserted by means of an external push-button, through a manual reset input. The three parts feature different combinations of watchdog input, manual reset input and output stage configuration, as shown in table 1. Each part is available in a choice of 9 reset threshold options ranging from 1.58V to 4.63V. The reset and watchdog timeout periods are fixed at 140ms (min) and 1.6s ...